Spray discharge nozzle



, V/ll FIG. 6

Sept. 9, 1952 w. B. THOMPSON SPRAY DISCHARGE NOZZLE Filed Oct. 26. 1950 FIG.5'

l NVE NTO R WAYNE ,B. THOMPSON HIS ATTORNEY Patented Sept. 9, 1952 SPRAY DISCHARGE NOZZLE Wayne B. Thompson, Winchester, Mass, assignor to Spray Engineering Company, Somerville, Mass., a corporation of Massachusetts Application October 26, 1950, Serial No. 192,236 7 Claims. (Cl. 299-1401) The present invention relates broadly to spraying apparatus for applying liquid coating material to the interior wall surfaces of hollow articles. More particularly, the present invention relates to spray discharge nozzles which are used with such apparatus and which are characterized by the fact that air is directed supplementally to flatten the main discharge of coating material to produce an elongated spray pattern.

It has been proposed heretofore to spray-coat the interior wall surfaces of hollow articles such as cylinders, tubes, pipes, cans, and the like by apparatus which transforms to a flattened or fan shape, with elongated spray pattern, a main discharge of coating material which is initially circular in cross section, the means of accomplishment involving the discharge of air supplementally in the direction of only one side of the main discharge. The action of this supplemental air causes the main discharge to have a fan shape with an elongated spray pattern and it also causes deflection of the spray discharge as a whole so that it is tilted to the axis of the main discharge orifice. also has the further effect of causing the major axis of the spray pattern to be at 90 to the axis of discharge of the supplemental jet, i. e., at

' 90 to the plane which intersects the supplemental jet orifice axis and the main discharge orifice axis. Stating this difierently, the major axis of the spray pattern remains transverse to the axis of the main discharge orifice, as in the case of conventional supplemental jet spray heads or spray guns having two opposed supplemental jets which strike the main discharge at opposite sides to flatten it, but the location of the major axis of the pattern of the deflected spray is such that said major axis and the axis of the main discharge are not coplanar, in contrast to such conventional supplemental jet constructions.

In coating apparatus such as referred to in the preceding paragraph, there is relative longitudinal movement between the article to he interiorly coated and the head of the spraying apparatus, so that the coating is applied interiorly along the length of the article, and there is also relative rotative movement between the article and the spray head so that coating is applied interiorly of the article circumferentially. But since the axis of relative longitudinal movement is coaxial with the main discharge orifice of the spray head, it necessarily follows that the major axis of the elongated spray pattern is transverse also to the longitudinal axis of the article to be coated. As a consequence, there is a very prac- But this action tical disadvantage in using such apparatus for coating the interior wall surfaces of hollow articles. Coating material is applied to the article interior in a narrow stripe because the relative rotative movement is along the major axis of the flattened spray pattern, as it were, in analogy to using a manual paint brush with the applying end moving along its major axis and so producing a narrow stripe regardless of the width of the brush. From this it follows that there is a rela:- tively large time duration for coating the article interior from one end to the other or along a given part of its length, and as a result there is a minimum machine output per minute, i. e., per time unit.

If, however, the major axis of the pattern of the deflected spray is not transverse to the axis of the main discharge. orifice and consequently to the longitudinal axis of the article to be coated, but instead is coplanar with the axis of the main discharge orifice, it necessarily follows that said major axis is also coplanar with the longitudinal axis of the article to be coated. As a consequence, the flattened spray discharge is applied to the article interior in a Wide hand because the relative rotative movement is alongthe minor axis of the flattened spray pattern, as it were, in analogy to using a manual paint brush with the applying end moving at to its major axis and so making a band as Wide as the brush. From this it follows that there is a relatively small time duration for coating the article interior from one end to the other or alonga given part of its length, and as a result there is a.

maximum machine output per minute, i. e., per time unit.

It is therefore the principal object of the present invention to provide for use with article interior coating apparatus a spray discharge nozzle characterized by the fact that although airis discharged supplementally in the direction of only one side of the main discharge of coating material, with consequent flattening and deflection of the spray as a whole, the major axis of the flattened spray pattern thus produced is coplanar with the axis of the main discharge orifice and hence coplanar with the longitudinal axis of the interior of the article to be coated.

To the accomplishment of this object and of such others as will appear hereinafter, the various features of the present invention reside in certain constructions, combinations, and formations of parts which are all fully described hereafter in this specification and are then set forth in the appended claims the subject matters of which possess advantages which will be readily apparent to those skilled in the art.

The various features of the present invention will be readily understood from reading this specification in connection with the accompanying drawing which illustrates the best physica1 embodiments of the invention at present known to the inventor and in which:

Fig. 1 is a detail view in side sectional elevation showing a nozzle constructed in accordance with end, of a spray head body with which the nozzle may be used, the bulk of this body being cut away and the embodiment being shown in operation producing the deflected and fansiia 'esspray which it is the principal object of the present in vention to achieve. Fig. 1 may be consideredas taken along the axis line A'A of Fig. '7, looking toward the left of that figure;

Fig. 2 is a view in cross section of the fanshaped' spray discharge, taken along" the'line 2 2 of Fig. I, which line 2- 2 is perpendicular to the axis of the'Fig. 1 spray discharge as a whole;

Fig. 3 'is a; view in front elevation of the nozzle illustrated in Fig. 1

Fig. 4 is a view inside elevation of the nozzle illustratedin Figs. 1 and 3;

Fig. 5 adet'ailvi'ew in sectional elevation taken-along the line 5'5 of Fig. 4;

Fig. 6 "is a'deta irview corres onding to Fig. 5 but" showing" arnodi'fied embodiment of the presem invention: g

Fig; 7 i's'a detail viewiri iront'eievatioii of the Fig. 1 nozzle showing the location of the ma r axis" of the elongateds'p'ray pattern produced by eiilbo'di Gilt 6f the preseiit in'vehtioii and alse'showiii'g copmnarity of that major axis wit'rithe' axis of'thfe ha'in discharge orifice, the spray-b ing sho'wii' cut oil by the plaiiewhieh'prod s s. n

Fig. 8 151a detail'v'i'ew in'front' elevatio'n of a sappiememai jet spray nozzle having any one conventional jet; this View showin the" deflection of thspiay' as'awhole arid the location of the ri iiafjdr' axis of the elongated spray patterriwhen Suppl n 'iental'air is discharged ocn'ventionany in the d ctiori'o fo'hly one side of the rriaindisand also" show ng the lack of co-planar'ity at" major axis with the axis of the main'dischargeori'fice. Iii Fig. 8 the spray is shown-cut on by aplane which is perpendicular to the'axis o-f the'spray as 'a whole. I

With reference to the 'drawings,' there is shown in-Fig'. 1 an embodiment of the present invention mounted upon the forward end of a spray head or spray gun body. Those familiar with thespraying art will recognize in Fig. 1 the fro'r'itfend on gun body in having'a centrai assage il for liqiiid 'coating material and in Which t ere is thre a'dedjthe rear portion of a liquid nozzle l2. A needle 13' located in the passage H seats at its end in tlie nozzle I 2 to shut off the flow of liqu but in' Fig'. 1 the needle 13 is shown in retracted'po'sition to permit liquid flow through the some 12. The body Hlis provided with anarinul'ai forward face 14 which communicates with a compresse air passage I5 extending r'ea'rwaidly in the body I 0 and forwardly of the 'annularface 'l ltheh'ody' H] has a cylindrical portion'l't? of reduced diameter the front face of which coinmunicate's with' a compressed air passage ll which also'extends rearwardly in the'body It; Further body structure is not'disclosed because gun body structure per se' forms no part of the present inthe present invention mounted on the forward vention. The above-named parts are well understood in the art and are sufficient to give a locus of mounting of embodiments of the present invention. It may be added, however, that the body ll] showing in Fig. 1 is to be considered as only the forward end portion of an elongated structure capable of being moved into and out of hollow articles so that their interiors may be coated.

With particular reference to'Figs'. 1' and 3-5, the spray discharge nozzle 18 there shown and which illustrates one embodiment of the invention claimed herein is provided with a cylindrical base 19 having an inner cylindrical surface 20 which fits over thebody forward portion I6 of reduced dia'fiiieter so as' to be rotatable thereon. Rearv'va'rdly the cylindrical base is is provided with an annular face'Z-I- which seats against the annular face [4 on the body it, and to hold the cylindricalbase l9, and therefore the nozzle 18 as a whole, seated in any desired rotative position, the base i9 is provided with an annular boss 22 which isengagecl'by 'the'i'nturned lip 23" (Fig. 1) of a lockingring Z'Nthread'e'd on the body l0, as is well understood. Forwardl'y of the cylindrical base IS the nozzle 1'8 isshown a's having'a frusto-coni'ca'l construction, both internally and externally, and at'the center o'f'the' smaller base or front of thisconstruction there is formed a circular orifice 25" in which the forward end of the liquid nozzle IZis located; as shown inFig. l. Compressed air from the body passage llp'asses into the space between the body IO and the'interi'or frusto-conical surface of the nozzle [-8; and the orifice ZS-thus forins th'e main discharge orifieercr the emission of liquid co'atingmaterial ariacompre 'sed air-for atomizing it. As i's'w ell understood, the spray discharge ofatomize coating'material which suona c'onstruc'tion'prod'uces is cone-shaped as a whole and isci-r'cular in cross section-in th absence of influences which would ai'ter'thecr'oss sectional shape. As is als'oweil understood; in' the absence of such influences the spray "a whole is 'coaxial with the main disl ifarg'e' orifice, i. e3, the spray is discharged along the axis 'o f the rriain discharge orifice. The front ration of the nozzle E8 is planar at to this axis:

As-ihdicatedabove, it is intended that in the use of an embodiment of" the present invention this'spray discharge which is initially circular in cross section be flattened to form an elongated spray pattern and also be deflected so that the axisof' the spray as a whole is tilted away from the axis of the discharge orifice 25. But it is also intended that concurrently the major axis or" the elongated spray pattern thus produced be coplanar withthe axis of the main discharge orifice, and not transverse to that orifice axis. To achievethis result, the presentinvention contemplates that the nozzle 18 be provided with a horn or projection-21 which extends forwardly from one side only of the exterior frusto-conical surface of the nozzle and which has a closed forward end. The projection 21 is provided interiorly lengthwise with a pair of parallel passages 28 for compressed air, and communication between these passages 28 and the air passage 15 in the body ii] is aiforded'by an annular air passage 29 formed in-the cylindrical base [9 of the nozzle 18. The side of the'projection 21 which is shown facing the main discharge orifice 25 is illustrated as made up-of a planar face portion 30 which slopes away from the nozzle front-face 26 at aslight angle and of a face portion 3| which merges with the face portion 30 and is ina plane parallel with the axis of the discharge orifice and at 90 to theplanar front face 26 of the nozzle [8. The precise structure of the face porprojection 21 in communication with the air passages 28, respectively. These ports3'2 lie in a plane, which may be called their axes plane, and this plane is perpendicular to the face portion 30, with the result that the axes of the ports 32 are tipped forwardly at a slight angle away from the nozzle front face 26 and hence at an angle slightly greater than 90 to the axis of the discharge orifice 25, as indicated best in Fig. 1. The axes plane of the ports 32 intersects the axis of the discharge orifice 25 and is tipped away from that orifice, and while the ports 32 are shown with their axes parallel, these axes may diverge or converge, if desired.

Spaced outwardly from the ports 32, the pro- -j ection face portion is shown as provided transversely with a second or intermediate pair of ports 33 which also extend into the projection 21 in communication with the air passages 28,

respectively. These ports 33 also lie in a. plane,

which may be called their axes plane, but this plane is preferably tipped rearwardly, i. e., in the direction of the front face 26 of the nozzle I 8 and angularly to the plane of the ports 32, with the result that the axes of the ports 33 are also I thus tipped rearwardly. The axes plane of the ports 33 intersects the axis of the discharge orifice 25 and is tipped toward that orifice, and while the ports 33 are shown with their axes parallel, these axes may diverge or converge, if desired.

The paired port structure in the illustrated projection 21 is completed by a transverse third or outermost pair of ports 34 which are formed in the projection face portion 3| and which also extend into the projection 21 in communication with the air passages 28, respectively. These ports 34 also lie in a plane, which may be called their axes plane, and these ports 34 are shown with said plane tipped rearwardly, i. e., in the direction of the nozzle front face 26, at the same angle as is the axes plane of the intermediate ports 33, with the result that the axes of the ports 34 are also thus tipped rearwardly. The axes plane of the ports 34 intersects the axis of the discharge orifice 25 and is tipped toward that orifice, and while the ports 34 are shown with their axes parallel, these axes may diverge or converge, if desired.

With further reference to the port structure above described and with particular reference to Fig. 4, theindividual ports 32, 33, and 34 extending in a row at each side of the longitudinal median line of the projection 21 are shown with their axes lying in a plane at 90 to the front face 26 of the nozzle l8. These two planes, which may be called the axes planes of the two rows, are parallel and equally spaced laterally from the opposite sides of the axis of the discharge orifice 25 and thus straddle that axis. In a given construction, however, these two axes planes could diverge or converge, if desired. Moreover, the axes of each pair of the ports 32, 33, and 34 illus trated are spaced apart transversely of the projection 21 a distance greater than the diameter of the discharge orifice 25, and it is preferred that each pair of these ports themselves be so spaced apart a distancegreater than the diameter of the discharge orifice 25. If the axes of each pair of ports 32, 33, and 34 diverge, these axes and port spacings would also be the case, while if the axes of each pair of ports 32, 33, and 34 converge, the amount of convergence should not be great enough to cause the axes to intersect the axis of the discharge orifice 25 or even to be tangential to the orifice itself. Stating the foregoing differently, whether the axes of each pair of ports 32, 33, and 34 are parallel, or diverge, or converge, the space between these axes along a line diametric of the main discharge orifice 25 is greater than the diameter of said orifice.

While the angularities of the axes of the ports 32, 33, and 34 to the nozzle front face 26 and to the axis of the discharge orifice 25 may vary to suit different conditions of use, and while it is within the contemplation of the present invention that there be less or more than three pairs of ports along the projection 27, it is preferred that in the embodiment shown in Figs. 1-5 and -7 the planes through the axes of the ports 33 and 34 be each tipped rearwardly at 30 to a line perpendicular to the axis of the main discharge orifice 25 and thatthe axes plane of the ports 32 be thus tipped forwardly at 7, this last being easily achieved by giving the projection face ,portion 30 a 7 slope and drilling the ports 32 perpendicularly thereto, as above indicated. The pairs of ports 33 and 34 may each have a diameter of .035" and the ports 32 may have the slightly greater diameter. of .040". The space between the axes of each pair of ports may preferably be .156" where the axes of these ports are parallel, and fo'r'use with these dimensions the diameter of the discharge orifice 25 may be .070". It is to be understood that none of the dimensions and angularities stated in this paragraph is critical, but they are set forth as practical examples because nozzles. exhibiting them have achieved the object of the present invention in commercial use.

In Fig. 8 there is illustrated a spray discharge nozzle 35 which may be considered as mountable on the body [0 for disclosure purposes so that from the central orifice 36 there may be discharged the usual conical spray of atomized liquid coating material coaxial with the discharge orifice 36. In order to flatten this discharge to transform it to a fan shape, as indicated at S, the nozzle is provided at one side only with a projection 31 in which a conventional supplemental air port 38 is formed with its axis onplanar with the axis of the discharge orifice 36,

as is well understood. Since there is only one port 33, the spray is deflected downwardly, viewing Fig. 8, with the result that the axis of the spray as a whole is tilted downwardly and forwardly from the axis of the discharge orifice 36, and the major axis .i-A of the elongated spray pattern produced is transversely at to the axis of the discharge orifice 36. Fig. 8 illustrates the condition described in the second paragraph of this specification, and from this it follows that with the Fig. 8 nozzle in use on the body It for coating the interior of hollow articles, there will result the undesirable operation which is set forth in the third paragraph of this specification. Stating the foregoing differently, Fig. 8 illustrates the very condition which it is the principal object of the present invention to avoid.

Referring now to Figs. 1-5 and '7, it will be seen that while air is discharged supplementally fromthe pairs ofports 32, 33, and 34 in the'direction of the main discharge, indicated at S, that supplemental air is not discharged in a plane coaxialwith the discharge. orifice 25 but insteadin spaced planes located at opposite sides of,- or straddling, the axis of that orifice. The result of this operation is to provide a wall of air along each of opposite sides of the maindischarge S so" that it is flattened laterally to a fan shape by a wiping action, as it were, and the elongated spray pattern thus produced, as indicated in Figs. 2 and 7, has its major axis A--A in a vertical plane with which theaxis of the discharge orifice 25 is coplanar. Simultaneously with this, flattening of the main discharge, it is deflected downwardly and forwardly as a whole, as-indicated in Figs. 1 and '7, because the ports 32,33, and 34 are located at one side only of the main discharge orifice 25, and as a result the flattened discharge S is applied to the interior of hollow articles in the desirable manner set forth in the fourth paragraph of this specification.

Air dischargedsupplementally from the pairs of ports 32, 33, and 34 thus serves the double purpose of flattening the main discharge along its sides so that the major axis A--A of the spray pattern produced is coplanar with the axis of the .discharge orifice 25 and of deflecting the spray as a whole so that the spray is not coaxial with the discharge orifice 25 but is projected in the general direction of the surface to be coated instead of being projected along an axis parallel thereto. Air supplementally discharged from the ports 32 initiates the deflection of the spray discharge-along with its flattening, and this deflection is further carried out by the air discharged supplementally from the ports 33 and '34. If these ports have the angularities above described for them and illustrated in Figs. 1 and 5, for examples, the flattened spray S as a whole will have substantially the angle of deflection shown in Fig. 1, but if it be desired that this angularity from the axis of the discharge orifice 25 be less than shown, a spray nozzle ISA (Fig. 6) may be provided which is in all respects identical with the nozzle l3 and to this extent has been given the same reference numerals, except that the intermediate pair of ports 33A, otherwise identical with the ports 33, have their axes parallel with the planar front face 26 of the nozzle instead of 30 theretoward, as described above. It will be noted, however, that even with this modification the axes plane of the ports 33A, i. e., the plane through these two ports, is disposed angularly to the axes plane of the innermost ports 32.

Depending upon the nature of'the liquid coating material with which a given embodiment of the present invention may be used, and also depending upon eddy currents which may be set up in a given environment where the nozzle may be in operation, there may occur a building up of the material on the front face 26 of the nozzle. If the nature of the material is such that particles thereof have no tendency to fly off the front face 26, or if such flying oil does not have an adverse effect upon the success of the spraying operation, nozzles made as above described produce commercially successful results. f, however, the material builds up at such a rate as to necessitate frequent cleaning and hence lowered machine output, or if particles which may fly off the front face 26 render inferior the coating operation performed, it is desirable that the deflected spray S as a whole have a locus which is spaced outwardly from-the nozzle front face 26- a greater distance than would otherwise be the case. To this end'the front of the nozzle 18 may be provided with a supplemental air port 39 the axis ofwhich is shown as parallel with that of the discharge orifice 25, asindicated in Figs. 1, 3, and 7. y This port 33 extends rearwardly in the nozzle 58 to its inner frustoeconical surface so as to'be in communication; with the air from the body passage H, and the port 39 is located between the projection 21'. and the discharge orifice 25. The axis of the port, 39, is also parallel to and equally spaced from, the planes in which lie the axes of the individual ports 32, 33, and at each side of the longitudinalmedian line of the projection 27, as indicated in Fig. '7, with the result that air supplementally discharged from the port 39 is directed between the air walls formed by the discharges from the ports 32, 33, and 34 in addition to being directed axially parallel with the axis of the main discharge orifice 25. It is to be, understood, .however, that in a, given constructionthe port 39 may be angularly disposed so that its. axis is tipped out of parallelism with the axisof the discharge orifice 25. In keeping with the exemplary diameters stated above for the discharge orifice 25 and the pairs of ports 32, 33, and 34, the diameter of the port .39 may be .040".

Nothing herein set forth is to be interpreted as limiting the various features of the present invention in the. scope of their application to use in connection with the particular structural details or the particular mode of operation selected for purposes of illustration and explanation. While the particulars of construction herein set forth are well suited to one mechanical embodiment of the invention, to the use to which it is put, and to the mode of operation disclosed, the invention is not limited thereto nor to the disclosed details of construction nor to the conjoint use of all the disclosed features. It is not to be understood that these particulars or details are essential since they may be variously modified within the skill of the artisan without departing from the true scope of the actual invention, the characteristic features of which are set forth in the following claims which intentionally use generic terms and expressions that are inclusive in meaning of various physical modifications.

What is claimed as new is:

l. A spray discharge nozzle having a main orifice for the discharge along an axis of liquid coating material and air under pressure to atomize the liquid; a projection extending from the front of the nozzle to one side of the main discharge oriflce and provided with air passage means; and a plurality of ports disposed in pairs along said projection in communication with said air passage means for the discharge of air supplementally along opposite sides of the main discharge to form an air wall at each of said opposite sides, the axes of each pair of ports lying in a plane which intersects the main discharge axis, the axis of each individual port being laterally spaced from the main discharge axis, the space between the axes of each pair of ports along a line diametric of the main dischargeorifice being greater than the diameter of said orifice, and'the supplemental discharges from said ports being unopposed by corresponding supplemental discharges directed from the opposite side of the main discharge, whereby the axis of the 1 main discharge is deflected from the axis of the main discharge orifice.

2. Structure such as set forth in claim 1 characterized by the presence of an additional supplemental air port located between the main discharge orifice and the projection.

3. A spray discharge nozzle having a main orifice for the discharge along an axis of liquid coating material and air under pressure to atomize the liquid; a projection extending from the front of the nozzle to one side of the main discharge orifice and provided with air passage means; and a plurality of ports disposed in pairs along said projection in communication with said air passage means for the discharge of air supplementally along opposite sides of the main discharge to form an air Wall at each of said opposite sides, the axes of each pair of ports lying in a plane which intersects the main discharge axis, the axes plane of the outermost pair of ports being angularly disposed toward the main discharge orifice, the axes plane of the innermost pair of ports being angularly disposed away from the main discharge orifice, the axisof each individual port being laterally spaced from the main discharge axis, the space between the axes of each pair of ports along a line diametric of the main discharge orifice being greater than the diameter of said orifice, and the supplemental discharges from said ports being unopposed by corresponding supplemental discharges directed from the opposite side of the main discharge, whereby the axis of the main discharge is defiected from the axis of the main discharge orifice.

4. Structure such as set forth in claim 3 characterized by the presence of an additional supplemental air port located between the main discharge orifice and the projection.

5. A spray discharge nozzle having a main orifice for the discharge along an axis of liquid coating material and air under pressure to atomize the liquid; a projection extending from the front of the nozzle to one side of the main discharge orifice and provided with air passage means; a plurality of ports located in said projection in communication with said air passage means for the discharge of air supplementally along opposite sides of the main discharge to form an air wall at each of said opposite sides, the supplemental discharges from said ports being unopposed by corresponding supplemental discharges directed from the opposite side of the main discharge, whereby the axis of the main discharge is deflected from the axis of the main discharge in communication with said air passage means for the discharge of air supplementally along opposite sides of the main discharge to form an air wall at each of said opposite sides, the axes of each pair of ports lying in a plane which inter sects the main discharge axis, the axes plane of the outermost pair of ports being angularly disposed toward the main discharge orifice, the

axes plane of the innermost pair of ports being,

angularly disposed away from the main discharge orifice, the axes plane of the intermediate, pair of ports being angularly disposed to the axes plane of the innermost pair of ports, the axis of each individual port being laterally spaced from the main discharge axis, the space between the axes of each pair of ports along a line diametric of the main discharge orifice being greater than the diameter of said orifice, and the supplemental discharges from said ports being unopposed by corresponding supplemental discharges directed from the opposite side of the main discharge, whereby the axis of the main discharge is defiected from the axis of the main discharge orifice.

7. Structure such as set forth in claim 6 characterized by the presence of an additional supplemental air port located between the main discharge orifice and the projection.

WAYNE B. THOMPSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

